The eSurge database consists of a set of surge events (SEVs), each of which is associated to a particular area of interest (AOI). The current AOIs are shown in the figure to the right; others may be added in the future.

For each SEV, the eSurge database makes available a range of satellite, model and in-situ data across the associated area of interest, and within a specified timeframe. This data is available for users to browse, preview and download.

Some of the AOIs overlap, especially around the European coastlines. This is to allow flexibility in capturing events. For example, for an event in the Irish sea we could choose to look at only local data within the sea, in which case the event is assigned to AOI-20, or we can say that the event is connected to wider patterns, in which case we might assign it to AOI-30. In some cases there may be two SEVs in order to capture data in both regions, for example if the same storm causes surges in both the North and Baltic seas.

We recognise that there will be some ambiguity about how the assignment of SEVs to AOIs is made, and we would welcome feedback as to how it works in practice.

The main data access page has a clickable map and list of the current Areas of Interest. Clicking on any of the AOIs will bring up a table of surge events associated to that AOI. The table lists the event, its nominal date, and the dates before/after the event for which data are collected.

If you cannot find a particular event that you are looking for, you can:

Within (4), for each type of data there is a link ("Product info") to the background information on that particular data type. Clicking on the symbol lists the available data sets within each data type (see next section). A link to the product handbook for that data will also be added.

The previous step shows how to find the list of available data types for a given surge event. Within each data type, pressing the symbol will open up a list of available data sets for that type.

For each data point, the table lists the file name and the time stamp (UTC), as well as links to the preview and OPENDAP functionalities, plus a checkbox for downloads.

For any data set, selecting the "Preview" link on the right will open an overlay window displaying the contents of the data file, as in the figure on the right.

It is possible to expand the preview to fill the screen, while clicking on the left/right sides of the image allows the user to scroll back/forward through the catalogue for that data set.

This functionality is intended to give users an idea of how useful the final data set will be before downloading it, rather than as a fully fledged display tool. More functionality is provided by the visualisation tool.

The visualisation tool allows data sets to be viewed, zoomed in on, superimposed with each other, etc.

When the tool is opened for a given event, it will show a map of the AOI and a list of available data types ("Overlays"). Selecting a data type will show a list of individual data points for that type. Selecting a data set will display it on the main map.

Once you have selected that data sets to be displayed, move to the "Selected Layers" tab. This allows the order and degree of transparency of individual layers to be changed.

The "Base" tab gives a choice of different layers to be used as the base map. This can be especially useful at small scales, for example allowing flood maps to be shown against street maps or satellite images.

Other functions are available by clicking on the small images above the map; see the tools own help page for a description.

At the moment this tool is a preliminary version, we hope to add more functionality in due course.

Once the user has decided which data sets they want to download, there are several ways to actually download this data.

If only a single data set is required, then click the "OPENDAP" link for that data set. This will open up an OPENDAP window like that one shown to the right. This allows downloading in binary or ASCII formats, as well as providing a direct link to our THREDDS catalogue.

Alternatively, to download multiple data sets, go back to the list of data sets for the SEV. Select the ones to be downloaded using the checkboxes to the left of each data set. Then scroll to the bottom of the page, and click the "Download wget script" button. This will download a script for downloading the data sets that you have selected.